An interesting piece of info concerning the 1800 mile hike I did on the Pacific Crest

[Different Socks]

As I made my way down to Yosemite Valley to pick up my next food supply, I was briefed by several other hikers that a huge slab of rock had fallen from Glacier Point, high above the valley floor. As luck would have it, my exit point from the trails was at ground zero of the impact zone of the arch of rock. As I walked towards the main part of the village I passed a campground that was completely empty. People had run for their lives so quickly that they had left everything behind. I walked past RV's, picnic tables covered with plates, utensils, cups, campers, coolers, bikes--and it was all covered in a film of grey dust that had exploded from the pulverizing impact of the arch hitting the ground after falling 2400 feet. There was no other colors of green leaves, brown bark, white campers or RV's, or anything else. Everything was grey. It looked like a modern day version off Pompeii, minus the mummified bodies. Because of my exit point I was one of the few people that were not rescue personnel to see the devastation and destruction that was wrought by this natural event.
Later it was discovered that the arch was massive in size: 95ft long, 130 ft high, 20ft thick and weighed 60,000 tons!! The impact upon the ground was equivalent to 100 tons of TNT!!!
Abnd it fell less than 24 hours before I had hiked down to the valley. Incredible!!

[Rasty]

Different Sock, when did this happen?

[rocketsocks]

Just for comparison that rock sounds like it was the size of three Olympic size pool at about 164ft x 82ft x 6ft,thats a lot of rock.

[Different Socks]

Summer of 1996. July 10. As I walked by the campground and other places nearby, every ranger(seriously) stopped and asked me who I was, where I had been bping, and where I had come off the trail. It was truly surreal. My only bad luck was that this was before digital cameras, and I was out of rolls of film to take any pictures.
I tried to slowly walk from the trail head to a bit closer to the initial impact area, but the explosive force had ripped out all trees within some distance of the impact site. When people had heard I had walked thru the impact area I was inundated with questions everywhere I went.

[Hoop]

The 1996 Yosemite Valley landslide occurred on July 10, 1996 near the Happy Isles trailhead in Yosemite Valley, Yosemite National Park, Mariposa County, California. 162,000 tons of rocks and other debris fell to the ground at over 160 miles per hour. Of 12 campers/hikers involved in the incident, one was killed. The landslide competes with the January 1997 Merced River flood for the designation of the worst natural disaster in Yosemite to date.

"At 6:52 pm PDT Wednesday, July 10, 1996, a large block of granite, with an estimated volume of 78,000 cubic yards, detached from the cliff between Washburn Point and Glacier Point, in Yosemite Valley."
—UC Berkeley Seismograph Station^[2]

The first impact occurred at 18:52:28.0 Pacific Daylight Time (02:52:28 UTC), and the second at 18:52:41.6 PDT (02:52:41 UTC).

"After detaching from the cliff, the rock mass slide [sic] down a rock shelf for 600 feet at an angle of 50 degrees from vertical and acquired sufficient speed to free-fall ballistically an estimated 1800 feet (550 m) prior to impacting about 200 feet (60 m) from the base of the cliff in the Happy Isles area of the valley floor in Yosemite National Park (field investigation with Gerald Wieczorak and Richard Waitt)."
—UC Berkeley Seismograph Station^[2]

One of the impacts killed a hiker near the cliffs.

[LeeAllure]

There's a Natural Geographic documentary on Yosemite which covers this (among other natural events which can affect people in the park) and shows it in much of its glory. It was available on Netflix.

[rocketsocks]

There's a Natural Geographic documentary on Yosemite which covers this (among other natural events which can affect people in the park) and shows it in much of its glory. It was available on Netflix.

cool,will look for this,thanks LeeAllure

[ChinMusic]

One of the impacts killed a hiker near the cliffs.

Dang, what a way to go.

[Veetack]

Dang, what a way to go.

No better way to go IMHO, quick and virtually painless doing something that you love. In a deadly beautiful place no less. When it's my time, I could only be so lucky.

[Different Socks]

Dang, what a way to go.

Yes it was unfortunate for that one hiker, but the park and its visitors were very lucky. The Happy Isles area has tourist business(es) and all of them were closed at the time the slab of rock hit the area. I was told by the rangers that questioned me that normally there would have been dozens of people all around those buildings.

[ChinMusic]

Yes it was unfortunate for that one hiker, but the park and its visitors were very lucky. The Happy Isles area has tourist business(es) and all of them were closed at the time the slab of rock hit the area. I was told by the rangers that questioned me that normally there would have been dozens of people all around those buildings.

If there hadn't been anyone there, would it have made a noise at all?

[Different Socks]

That day I walked into the valley I had been to the top of Half Dome and had it all to myself to see the sunrise. Imagine if I had been there the day before and witnessed that arch of rock breaking off and falling on top of Happy Isles??!! Course that also means I may have been at ground zero at the moment of impact.

[Different Socks]

If there hadn't been anyone there, would it have made a noise at all?

I know that was meant to be funny, but seriously........the people I met further down the valley gave me many different descriptions of what they heard and saw, yet they were 1/4--3/4 mile away, possibly further when it occurred. Gigantic cloud of dust that didn't dissipate for hours, the rock as it went into freefall made sounds of 100's of bowling balls impacting against each other, the trees that were snapped at the trunk stacked like a jumbled mass of pick up sticks, and much more that they told me.

[ChinMusic]

I know that was meant to be funny, but seriously........the people I met further down the valley gave me many different descriptions of what they heard and saw, yet they were 1/4--3/4 mile away, possibly further when it occurred. Gigantic cloud of dust that didn't dissipate for hours, the rock as it went into freefall made sounds of 100's of bowling balls impacting against each other, the trees that were snapped at the trunk stacked like a jumbled mass of pick up sticks, and much more that they told me.

I would imagine it would have been similar to the rolling cloud of dust after the twin towers collapsed, but more so.